A manual would be great and better for it eliminates mistakes which could not solve the problem at all and worse send you off buying a new board due to a short you created when you hastily did the operation. Boards come in several versions from several manufacturers, and if you’re like me who sticks to a select group of manufacturers, chances are they will have the overall same labels that allow easy understanding of the board even without the manual. If the reset pins come in the form of a three pronged arrangement, then there should be a jumper that shorts out two of them which in it’s current state would be the normal setting, switch the pins using the jumper and short the pins labeled reset, wait for a few minutes for the bois to reset then return the pins to the normal position. Some boards have labes some don’t and have numbers that have to be referenced with the manual.